Alexandria cycad description

The Alexandria cycad is a member of an ancient plant group, the cycads, which flourished over 150 million years ago alongside the dinosaurs. Today, there are only around 300 living species of cycad, occupying a small fraction of the group’s former range (4)(5)(6). One of the most attractive of the South African cycad species is the Alexandria cycad, a multi-stemmed, medium-sized plant, with numerous grey-green leaves that recurve towards the tips (2)(6)(7)(8). Although the stems may grow up to two metres long, they are usually partially concealed by sand and leaf mould. As with all cycads, the male and female cones of this species, which are both light green at maturity, are borne on separate plants (2)(8). In addition to the common green leaved form, there is a rarer and smaller blue-leaved form that occurs in a small number of localities (2)(7)(8).

Related species

Alexandria cycad biology

Cycads are long-lived, slow growing plants that always occur as individual male or female plants (6)(7). There is no way of determining the sex of a cycad until it begins to produce its first cone (7). For a long time cycads were thought, like cone-producing conifers, to be entirely wind pollinated(9). However, studies now suggest that the vast majority, if not all cycads, are actually pollinated by insects or more specifically weevils (6)(7)(9). To attract pollinators, male and female cones produce powerful odours, usually in the early morning or evening (7). Travelling between the sexes, the weevils pollinate the plants by inadvertently transferring pollen from the male cones to the receptive ovules of the female cones (7)(10).

The seeds produced by cycads are large and have a fleshy outer coat, but are relatively short-lived and vulnerable to desiccation. The fleshy outer layer is desirable to a range of animals such as birds, rodents and bats, depending on the species of cycad and region it occupies. However, with any luck the unpalatable seed is discarded some distance away from the parent plant in a hospitable environment in which to germinate(6).

Alexandria cycad status

Alexandria cycad threats

Although it was once plentiful across its range, the Alexandria cycad is now relatively rare in the wild, with a population size of just 850 to 1,500 mature individuals (1)(2)(7)(8). Although clearance of habitat for farming was the main cause of its decline in the early 20th century, in more recent times, large numbers of this species have been removed by collectors (7)(8).

Authentication

Glossary

The beginning of growth, usually following a period of dormancy and in response to favourable conditions. For example, the sprouting of a seedling from a seed.

Ovules

A structure within the female reproductive organs of plants that contains eggs and when fertilized by pollen, develops into seeds

Pollinate

To transfer pollen grains from the stamen (male part of a flower) to the stigma (female part of a flower) of a flowering plant. This usually leads to fertilisation, the development of seeds and, eventually, a new plant.

Pollinators

Animals that in the act of visiting a plant's flowers transfer pollen grains from the stamen (male part of a flower) to the stigma (female part of a flower) of a flowering plant. This usually leads to fertilisation, the development of seeds and, eventually, a new plant

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